Uh, its not like the people who don't want to secede have to stay. Mass migration, then civil war, then The Neo-American Union intervines, and soon Russia, along with Israel, assist the traitor states. Big explosions, gun fire, and dead bodies everywhere. Then the President is moved to a safe house, only to be taken hostage by one of his head security. The Confederates then make a deal with the NAU to withdrawl their troops and to migrate down to Mexico if they want their president. Then accept, but then the UK sends SAS and assassinate the Southern Head Honcho and then back to fighting.
bye cumrod